Paul karrer



10. any

Patented Nov. 29, 192'].

onnnn STATES em nnnoeeiee.

PAUL KARE-ER, OF ZURICH, SWITZERLAND, .ASSIGNGR- TO CHEMICAL WORKS FOBJQEBLY LAHDOZ, OF BASEL, SXVITZERLAND.

rnocnss non THE rnxmine'rzon or core-son axman-s.

m; Drawing. Appllatton filed Mareh 6, 1926. Serial No. 92,953, and in a m-many March 11, 1825.

It has been found that cotton fibers, which are more or less esterified with toluene sulphonic, benzene sulphonic and naphthalene sulphonic gmups or with :u'yland alkylsul- 6 honic oops-of any kind, can be altered y treating them with inorganic basic nitrogen compounds, for instance ammonia, hyrlra'zine etc., so that the fibers are capable of being directly dyed with acid dyestuffs of kind.

The process can he performed by treating the above mentioned esterified cotton fibers with these substances, pure or dissolved in suitable solvents, which are not injurious to 15 the fibers, for example water, alcohol eto or by treating the fibers in the cold with the above mentioned agents. Ammoniat for instance can also be employed in form of gas.

The following example illustrates the in- 0 vention without however limiting its scope,

the parts being by weight.

10 parts of cotton, partially es'terified by v toluene sulphonic groups, are heated with 50 parts of a 2 12i,- nnti-l zinnnonia solution -for 6 hours in on uniorlzia'r ."it 1W)" The 2-) acid d vrslnflk, r-onfii ling in treating cotton 35 fibers w ich are partially (SlOX'lfiOll with an organic sulphonir: group. with an inorganic basir nitrogen r-onipouwl.

2. A pro 5 for the preparation of cotton .fibm's' in View of their (lira-rt dyeing with 49 acid tlye tufl rorwisling in treading cotton fibers whi l! arr pnrlinllz' rti-rilir-rl Willi on organic sulphonir: gr up. \"ilh ammonia.

In witness whereof l lmi'r'heri-nnto :iQm-il toy-name thi= 17th lay of F 'ln'llilfl'. 191 .6. PAUL KARRER. 

